Anthem MRX-SLM – Ultra-Compact 5.1 AV Receiver

The Anthem MRX-SLM is a 5.1 AV receiver in a slim-line chassis that packs complete home theater electronics, including ARC Genesis room correction, into a footprint of roughly 28 × 28 centimeters and barely four centimeters of height. It's built exactly for the case where a normal receiver simply doesn't fit: behind the wall-mounted TV, under the shelf, in a shallow piece of furniture.

Why the MRX-SLM?

Because it's the opposite of a compromise, even though it looks like one. ARC Genesis – the same calibration software that runs in Anthem's big preamps – is on board, measurement microphone included. Precisely where the SLM gets used, a speaker rarely stands ideally, and that's exactly where room correction pays off the most. The Class D power amps stay cool enough that the unit survives even a closed cabinet. The wall bracket is included, a 19-inch rack kit is optional: the SLM is meant as an installation device, not shelf decoration.

What you'll hear

Five channels plus subwoofer, with genuine Dolby Atmos and DTS:X decoding. Out of the box it runs as 5.1. Via amp matrixing you repurpose the two surround channels – onto two height speakers for 3.1.2, or for bi-amping the front speakers. Picture passes through via HDMI, sound comes back from the TV via eARC, and music plays over AirPlay, Google Cast, Spotify Connect, or Bluetooth. You don't need a subscription for that: whatever's connected to the TV and whatever comes from your phone plays anyway, at no extra cost.

Who is the MRX-SLM for?

Straight talk: the SLM is for rooms where the technology should disappear – living rooms with a wall-mounted TV, a second cinema, bedroom, practice, holiday apartment, built into furniture. It's not made for the big cinema room: a single HDMI input, no preamp outputs besides the subwoofer, no second zone, no 8K, and no 4K/120 for the games console. If you want to connect several picture sources directly, or grow to seven channels later, the MRX 540 or bigger is the right call. But if you've been wondering where to put the receiver, you can stop wondering.

Our verdict

The MRX-SLM solves a problem many beautiful living rooms have: real multichannel sound without a visible tower of gear. Anthem room correction, clean bass management, and five decent power amps in a chassis you'll hardly find if you don't know where it's mounted. Whether it suits your room, your TV, and your speakers, we're happy to sort out in advance – HD Zürisee in Wädenswil, +41 44 680 22 00 or WhatsApp 076 534 22 00 (text only, no calls).

"The MRX SLM is a full-featured AVR, packing in the build quality and virtually every feature and configuration option that you'd expect from its bigger Anthem brothers." – John Sciacca, Residential Systems, 2025

Technical specifications

• Type: slim-line AV receiver, 5 channels (5.1), one zone
• Amplifier technology: Class D
• Power: 50 W into 8 ohms or 92 W into 4 ohms per channel, two channels driven
• Speaker impedance: 4 ohms or higher
• Channel configuration: 5.1 out of the box; via amp matrixing 3.1.2 with two height speakers or bi-amping the fronts
• Decoding: Dolby Atmos, Dolby TrueHD, Dolby Digital, DTS:X, DTS-HD, PCM; upmixers AnthemLogic, Dolby Surround, DTS Neural:X
• Room correction: ARC Genesis incl. USB measurement microphone
• HDMI: 1 input, 1 output, HDMI 2.0b, HDCP 2.3, output with ARC and eARC
• Video: up to 4K/60 Hz, HDR10 and Dolby Vision; no HDMI 2.1, no 4K/120, no VRR/ALLM, no 8K
• Additional inputs: 1 × optical (Toslink), 1 × analog 3.5 mm jack
• Outputs: 1 × subwoofer; no further preamp outputs
• Headphone output: not available
• Speaker connection: 10-pin pluggable Euroblock terminal block
• Network and streaming: LAN 10/100, dual-band Wi-Fi, Apple AirPlay, Google Cast, Spotify Connect, Bluetooth
• Control: Anthem app, web interface, remote control, external IR input, IP control
• Radio tuner: not built in
• Mounting: wall bracket included, rubber feet, optional 19-inch rack kit (1U)
• Power consumption: typically under 50 W, standby with IP control under 2 W
• Dimensions (W × H × D): 27.9 × 3.8 × 27.9 cm without feet; 4.3 cm high with feet, 4.4 cm (1U) in rack; 33 cm depth including power cable
• Weight: 3.0 kg
• Origin: Anthem, Canada
• Included: receiver, remote control with batteries, USB measurement microphone with cable, two Wi-Fi antennas, power cable, universal wall bracket, external IR receiver, 10-pin speaker terminal block, self-adhesive rubber feet, quick guide, warranty card

Frequently asked questions

Does the MRX-SLM really fit behind a wall-mounted TV?

Yes, that's exactly what it's built for. At roughly 28 × 28 centimeters footprint and 3.8 centimeters height without feet, it disappears behind most wall-mounted TVs. The matching wall bracket is included; alternatively, you mount it under a shelf, inside furniture, or with the optional kit in a 19-inch rack.

Can the Anthem MRX-SLM do Dolby Atmos?

Yes, it decodes Dolby Atmos and DTS:X. Out of the box it works as 5.1 with no height channels. Via amp matrixing you repurpose the two surround channels and run 3.1.2 with two height speakers. Then you hear Atmos with genuine height information instead of just a downmix to the plane.

How many HDMI connections does the MRX-SLM have?

One input and one output, both HDMI 2.0b with HDCP 2.3. The output supports ARC and eARC, so the TV takes over switching picture sources and sends the sound back. Add an optical digital input and an analog 3.5 mm input for further sources.

Is 50 watts per channel enough for my living room?

In small and medium rooms, yes. The MRX-SLM delivers 50 watts into 8 ohms and 92 watts into 4 ohms per channel with two channels driven. With efficient compact or built-in speakers and an active subwoofer, that easily carries a movie night. It's deliberately not designed for large cinema rooms.

Why buy the Anthem MRX-SLM at HD Zürisee?

Because a hidden device deserves to be set up properly, if anything more so. As an authorized Anthem dealer in Wädenswil, we work out placement, speaker match, and wiring with you. Mauri, our own technician, mounts it, wires it, and calibrates with ARC Genesis. Call +41 44 680 22 00 or write to shop@hdzuerisee.ch.

Goes well with this

For the speakers around it, it's worth a look at speakers and home theater. If you're letting the SLM disappear cleanly into furniture, plan for proper cables right away – badly routed cables get expensive fast, well-bought ones don't. The whole brand is under Anthem, more units among the AV receivers.